Whole note tremolo outside staff

[Lasse]

> I'm not top posting

%% Whole note tremolos for notes outside the main staff have their tremolo beams
%%  printed in the ledger lines. However, by common practice the whole note 
%%  should be treated as if it had a stem, and hence the tremolo beams should 
%%  be in the same vertical position as they are for the eigth notes that 
%%  follow; i.e. the lowest tremolo beam for the whole note should be on the 
%%  middle line of the staff.
%% The analogous usage should be implemented for notes below the staff.
%% (We have no explicit style reference for this, but it is common usage in 
%%   music engraving; see e.g. Tschaikovsky 'Romeo and Juliet', high strings, 
%%   measures 452 and 460, Dvorak, Symphony No. 8 (New World), first movement,
%%   letter G; Strauss, Salome, one bar before rehearsal number 68, etc.)
%% Thanks to Mark Polesky and Werner Lemberg for confirming this - see also 
%%  the lilypond-user discussion on "Whole note tremolo repeats - bug?"

\version "2.12.0"
\paper{ ragged-right=##t }
\relative c'''' {
  c1:16
  c8:16 c:16 c:16 c:16 
}